The invention is useful in machine knitting on a weft knitting machine having independently operable needles disposed in at least two needle beds, for example, a flat V-bed machine producing a mainly double jersey structure. In such machines, the width of the knitted fabric is restricted by the maximum number of needles available for forming a course across the machine bed.
Three-dimensional fabric structures for covering three-dimensional objects are produced from two-dimensional material and have in the past been produced by weaving or knitting shaped parts and panels of two-dimensional material and sewing them together.
More recently, it has been found possible to continuously knit one-piece upholstery fabric, which removes the need for sewing portions together, and has the desired shape to serve as covers for the base and back cushions of motor vehicle seats; see, for example, U.S. Pat. Nos. 5,308,141 and 5,326,150. The shaping of covers is accomplished by joining together edges of areas of fabric during the knitting process so that the wales on opposite sides of the join are inclined relative to each other. When a large number of wales are joined together on a course-by-course progression, the join manifests itself as a suture line.
Suture lines, as well as being visual, may give rise to hole formation at the joins between wales on each edge. U.S. Pat. No. 5,038,585 discusses in detail the problems associated with continuous knitting of edges-to-be-joined.